• by June 13, 2007

London-based Openads, which claims its free open source ad server is the world's most popular, has secured $5 million in Series A financing led by European venture capital firm Index Ventures, with participation from First Round Capital, Mangrove Capital Partners and O'Reilly AlphaTech Ventures. The company, which was originally a technology division with Unanimis, became a stand-alone business this month.

Openads said it is used by more than 20,000 publishers--more than all its competitors combined.

The move comes in the midst of increasing industry speculation that Google plans to make its ad servers free. The search giant's DoubleClick acquisition would give it that firm's ad server in addition to AdSense.

Index Ventures has previously invested in such companies as Skype and MySQL.

With the new investment, Bernard Dalle and Saul Klein from Index Ventures, and Gerard Lopez from Mangrove Capital, will join Damon Reeve from Unanimis on the Openads board of directors.